diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexBugsTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexBugsTests.java
index 948c371ecaf..55aa0d2dd42 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexBugsTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexBugsTests.java
@@ -60,6 +60,7 @@ import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IProjectDescription;
 import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Path;
 
@@ -1041,5 +1042,39 @@ public class IndexBugsTests extends BaseTestCase {
 			fIndex.releaseReadLock();
 		}
 	}
-
+	
+	// #ifndef GUARD
+	// #include "source.cpp"
+	// #endif
+	public void testIncludeSource_Bug199412() throws Exception {
+		StringBuffer[] contents= getContentsForTest(1);
+		final IIndexManager indexManager = CCorePlugin.getIndexManager();
+		IFile f1= TestSourceReader.createFile(fCProject.getProject(), "source.cpp", contents[0].toString());
+		waitForIndexer();
+		
+		final ITranslationUnit tu= (ITranslationUnit) fCProject.findElement(new Path("source.cpp"));
+		Thread th= new Thread() {
+			public void run() {
+				try {
+					tu.getAST(fIndex, ITranslationUnit.AST_CONFIGURE_USING_SOURCE_CONTEXT);
+				} catch (CoreException e) {
+					CCorePlugin.log(e);
+				}	
+			}
+		};
+		fIndex.acquireReadLock();
+		try {
+			th.start();
+			th.join(5000);
+			assertFalse(th.isAlive());
+		}
+		finally {
+			try {
+				th.stop();
+			}
+			finally {
+				fIndex.releaseReadLock();
+			}
+		}
+	}
 }
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/TranslationUnit.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/TranslationUnit.java
index 95f5a2e00c6..61adf23500d 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/TranslationUnit.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/TranslationUnit.java
@@ -19,6 +19,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 
@@ -789,8 +790,11 @@ public class TranslationUnit extends Openable implements ITranslationUnit {
 				IIndexFile context= null;
 				IIndexFile indexFile= index.getFile(IndexLocationFactory.getIFL(this));
 				if (indexFile != null) {
+					// bug 199412, when a source-file includes itself the context may recurse.
+					HashSet visited= new HashSet();
+					visited.add(indexFile);
 					indexFile = getParsedInContext(indexFile);
-					while (indexFile != null) {
+					while (indexFile != null && visited.add(indexFile)) {
 						context= indexFile;
 						indexFile= getParsedInContext(indexFile);
 					}
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMFile.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMFile.java
index e84a571b23a..551287fa8a4 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMFile.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMFile.java
@@ -6,9 +6,9 @@
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
- * QNX - Initial API and implementation
- * Markus Schorn (Wind River Systems)
- * Andrew Ferguson (Symbian)
+ *    QNX - Initial API and implementation
+ *    Markus Schorn (Wind River Systems)
+ *    Andrew Ferguson (Symbian)
  *******************************************************************************/
 package org.eclipse.cdt.internal.core.pdom.dom;
 
@@ -107,6 +107,10 @@ public class PDOMFile implements IIndexFragmentFile {
 		return false;
 	}
 
+	public final int hashCode() {
+		return System.identityHashCode(pdom) + 41*record;
+	}
+	
 	/**
 	 * Directly changes this record's internal location string. The format
 	 * of this string is unspecified in general and is determined by the